It's sounds like you've done a bit of homework, as would be expected of someone with your background. However, when selecting a partner, make sure you spend a great deal of time getting to know them. I can't stress that enough.
Also, I'd encourage you to solicit people that have similar interests (possibly expertise in something you wished you knew more about & enjoy), which can potentially turn into your product/business. If you want to spend a significant portion of your life working on something, it might as well be something you enjoy (cause you can grind out a living doing things you don't care about for anyone). When recruiting engineers, let them know what spaces / ideas you are considering. From my experience, passion for a space gets more responses then delineated qualifications.
Unfortunately, yes. I'm not sure if it's directly related to the fact that HR is a high volume function and there aren't any objective metrics that track how gracefully non-selected candidates are degraded or if legally, it's better to say nothing at all. I also have some suspicions that many posted jobs are posted on spec, which is to say that they are 'in the pipeline', but not authorized to actually hire.
In the current job market, it's easy to get sloppy with practices like these. It is rude, but such is life.
Personally, I've had endless reschedules, interviewer no shows, long dark periods (even when the outcome has been positive) and no response (after being flown for on-site interviews). It's not specific to company size, stage, industry, location, etc. As I mentioned above, it probably has to do with a lack of managing the feedback loop of non-selected candidate satisfaction.
First of all, what did the people who used the product say? Then, check and see if the analytics matches what they are telling you. Then you'll know if they are honest.
Generally, if your site is open to the public and not growing, the beta testing group wasn't thoroughly impressed. Granted, that'll only hold true if your F&F are really apart of your target market. If they are just checking to see what you've done with your free time, they aren't gonna help your case.
But not all is lost. Coryl's response was right on. Find the people with the problem and pitch them your solution. If you have a solution to a pain point, pain killer v. vitamin, your users will evangelize for you...that being said, it always helps to have a product that gives them the ability &/or encourages them to do so. Just don't abuse it.
How I got beta testers?
1) I became active in startup groups and often engage in conversations via message boards, forums, startup groups and social networking sites. By doing so, when it's time for me to ask for a favor, people are genuinely curious and interested in checking it out.
2) I've spent a lot of time networking with startup people a couple (or more) steps ahead of me. First they provided me with valuable feedback and I supported them in whatever way I could. Then, when I was ready to launch, I sent them an invite to test and asked them for a tweet. It's innocuous and drives get traffic. Turns out, startup people follow startup people...who knew.
It shouldn't take more than 20-30 users, that go from signup through value proposition to generate the beginnings of viral growth. If you don't get the desired results from a batch that size, figure out what's broken and fix it. Once you understand how people matriculate through your website, verify the value proposition and start seeing the benefits of user / evangelists, then you can figure out how to drive more significant traffic.
I wouldn't pay for traffic until you understand the aforementioned nuances of your site.
Also, I'd encourage you to solicit people that have similar interests (possibly expertise in something you wished you knew more about & enjoy), which can potentially turn into your product/business. If you want to spend a significant portion of your life working on something, it might as well be something you enjoy (cause you can grind out a living doing things you don't care about for anyone). When recruiting engineers, let them know what spaces / ideas you are considering. From my experience, passion for a space gets more responses then delineated qualifications.
Best of luck.